Slide fasteners are widely used as opening and closing tools for dairy necessaries such as clothing items, bags, shoes and sundries, as well as for protective clothing items such as space suits, chemical protective clothing, diving suits, lifeboats and survival suits, and covers for shipping containers, tents and the like. For such special applications, waterproof properties are also required for the slide fasteners.
In general, the slide fastener is mainly composed of three parts: a pair of elongated fastener tapes; fastener elements which are engaging parts for the fastener and are attached along one side edge of each tape; and a slider for controlling opening and closing of the fastener by engaging and disengaging the fastener elements. Conventionally, a slide fastener is known in the art, which exhibits the waterproof property by affixing a synthetic resin film having the waterproof property to the fastener tape in order to provide the waterproof property and closely contacting the synthetic resin films of right and left fastener tapes during engagement.
For example, Japanese Patent Application Public Disclosure (KOHYO) No. 2002-525143 A1 (Patent Document 1) discloses that a water resistant film such as a polyurethane film is attached to one side of a fastener tape in a slide fastener by a transfer lamination method using nip rollers or laminating rollers. It also discloses that the film is preferably a multilayer structure including an outer wear resistant layer and an inner layer having a low melt material. It discloses that the provision of the wear resistant layer enhances the wear resistance and reduces the coefficient of friction to allow for ease of operation, and embedding of a portion of the low melt layer into the material of fastener tapes enhances adhesion of the film to the fastener tape. It also discloses that the polyurethane film is coated with an inner layer composed of a polyurethane adhesive, a binding agent or a hot melt adhesive.
Taiwan Patent Application Publication No. I220106 A1 (Patent Document 2) describes a method for forming a waterproof layer by pressing a PU sheet with a release paper onto a fastener tape coated with a PU gel by a roller apparatus to bond the PU gel and the PU sheet, followed by thermoplastic bonding of the PU sheet to the PU gel by heating.
Japanese Patent No. 43121 71 B1 (Patent Document 3) describes a method for forming a waterproof thin film by permeating a liquid polyester synthetic resin-based waterproof material into a fastener fabric tape structure.
Japanese Examined Utility Model Application Publication No. H01-14168 A1 (Patent Document 4) discloses that a fastener tape is coated with a synthetic rubber such as a silicone rubber, a butyl rubber, neoprene, a polyurethane rubber or the like as a waterproof sealing layer, dried and deposited.
Japanese Patent No. 3580725 B1 (Patent Document 5) discloses that a laminated synthetic resin film composed of a low melting point resin layer and a high melting point resin layer is deposited on at least one side of a fastener tape in a slide fastener by applying heat and pressure such that the low melting point resin layer is faced with and in contact with the fastener tape surface. As materials of the laminated synthetic resin film, urethane-based resins and polyester-based resins are disclosed.
Japanese Patent No. 5387912 B1 (Patent Document 6) describes a method for extruding a coating layer made of polyurethane, polypropylene, polyvinyl chloride and rubber thermoplastic material onto a surface of a fastener tape. More particularly, the method comprises feeding the fastener tape to an extrusion die and extruding a coating layer of a waterproof polymer onto the surface of the fastener tape to form a waterproof layer.
Japanese Patent Application Public Disclosure (KOKAI) No. 2012-24573 A1 (Patent Document 7) discloses that a surface of a fastener tape is coated with a fin-shaped polymer material whose element side is expanded. It also discloses that the coating of the polymeric material is extruded into a tape. The polymer material includes thermoplastic elastomers such as polychloroprene, polyurethane elastomers and polyester elastomers. According to the document, a pair of fin-shaped polymeric materials can be sealed with each other during closing of the slide fastener, so that a liquid sealed state can be formed at the contacted surface of the polymeric materials.